The present invention provides a thread groove pump mechanism which suppresses a backflow of the gas in the thread groove pump mechanism and reduces the pressure difference in the pump radial direction near the outlet of the thread groove pump mechanism to thereby improve the exhaust performance and the compression performance. The present invention also provides a vacuum pump including the thread groove pump mechanism, and a rotor, an outer circumference side stator, and an inner circumference side stator used in the thread groove pump mechanism. A thread groove pump mechanism includes an exhaust-performance improving means in an outer-circumference-side thread groove portion engraved on an opposite surface of an outer circumference side stator opposed to a rotor cylinder portion and an inner-circumference-side thread groove portion engraved on an opposite surface of an inner circumference side stator opposed to the rotor cylinder portion.

To provide a vacuum pump that is capable of efficiently cooling gas and requires less maintenance. The vacuum pump includes: a main body casing having an inlet portion and an outlet portion for gas; a turbomolecular pump mechanism portion in which a stator blade and a rotor blade are formed; a thread groove pump mechanism portion provided at a downstream side of the turbomolecular pump mechanism portion; a cooling trap portion that cools the gas led out from the turbomolecular pump mechanism portion and causes the gas to flow out to a side of the thread groove pump mechanism portion; and a partition wall that guides the gas led out from the turbomolecular pump mechanism portion to the cooling trap portion.

The present invention provides a vacuum pump that prevents invasion of foreign matter, such as rust and particles caused by a process gas, during the process of manufacturing a semiconductor wafer, and a flexible cover and a rotor that are used in the vacuum pump. A vacuum pump has a casing that has a gas inlet port and a gas outlet port, a rotor that has a recessed portion opened toward the gas inlet port and is fastened to a rotor shaft by a bolt disposed in the recessed portion. The recessed portion is provided with a flexible cover that has an outer peripheral portion supported on an end surface of the rotor that opposes the gas inlet port, and a central portion caved in the recessed portion of the rotor, the flexible cover covering the recessed portion by elastically deforming into a convex shape toward the recessed portion.

A rotor of a vacuum pump has a circular member that is driven rotatably, a cylindrical member joined to an outer circumference of the circular member, and a thread groove pump flow path formed between the cylindrical member and a stator member surrounding an outer circumference of the cylindrical member. The cylindrical member is made of a material having at least a feature of lower thermal expansivity or lower creep rate than that of a material of the circular member. A gap of a second region provided between a non-joint portion of the cylindrical member and the stator member is set to be smaller than a gap of a first region provided between a joint portion of the cylindrical member and the stator member.

A thread groove pump portion, which is an exhaust element, is structured such that a Siegbahn structure is attached onto a cylindrical thread, and such that respective parts are connected to each other at this attachment section. A flow channel of the Siegbahn portion and a flow channel of the cylindrical thread (the thread groove pump portion) are connected to each other so as to substantially form a right angle when viewed from an axis direction of the vacuum pump, thus, the flow channel of the Siegbahn portion and the flow channel of the thread groove pump portion are connected to each other. the length of a compression flow channel of the thread groove pump portion can be increased in a radial direction due to the connected Siegbahn portion.

Provided is a vacuum pump that prevents the solidification of gas while being operated properly. The vacuum pump includes a rotor that is supported rotatably on a base, a stator that has a thread groove portion, and a heating structure that heats the stator. The heating structure has a spacer that insulates the stator from stator components other than the stator, and a cartridge heater that heats the stator. The distance between a rotor cylindrical portion and the stator at the inlet port side is set to be equal to or greater than the distance between the rotor cylindrical portion and the stator at the outlet port side.

Examples herein relate to cooling systems. In one example, a cooling system comprises a plurality of adjacent fan modules configured to generate a plurality of cooling flows, a fan cage having a central axis adapted to contain the plurality of adjacent fan modules, the fan cage comprising a cavity on its central axis. Furthermore, the system comprises a first support bracket adapted to support the fan cage such that the fan cage rotates on its central axis and a bush established in the cavity of the fan cage. A first end of the bush is adapted to engage the first support bracket on a first surface of the fan cage.

An improved split flow vacuum pump is provided with at least two of compound pumps housed in a common housing comprising first, second, third and fourth inlets for receiving gas from a respective first to fourth chamber; said pumps are arranged such that their rotational axis are angled relative to each other in the housing, preferably perpendicular to each other.

A rotor of a vacuum pump has first and second cylindrical bodies and a connecting portion for connecting the end portions of the cylindrical bodies together. The first cylindrical body has a plurality of rotor blades on an outer circumferential surface thereof, and configures a blade exhaust portion when the rotor blades are arranged along an axial center of the vacuum pump alternately with a plurality of stator blades. The second cylindrical body configures a threaded groove exhaust portion when a threaded groove exhaust flow passage is formed at least on an inner circumference of the second cylindrical body. In this rotor, a balancing portion for the rotor is provided on an inner circumferential surface of the first cylindrical body or the connecting portion, and mass adding means is provided in the balancing portion.

The invention relates to an adapter for vacuum pumps, characterized in that it comprises an annular inlet flange (15) intended to be coupled to an outlet orifice of a chamber and an outlet coupling (16) comprising at least two cylindrical outlet through-housings (21) and forming an at least partial pump casing for the case (4) of a respective turbomolecular vacuum pump (3), said turbomolecular vacuum pumps (3) being intended to be received in a respective cylindrical outlet housing (21). The invention also relates to a pumping device, characterized in that it comprises an adapter for vacuum pumps (2) as described hereinabove and at least two turbomolecular vacuum pumps (3) housed at least partially in a respective cylindrical outlet housing (21).